Of course, just because there's a correlation doesn't necessarily mean scientists have found a cause. But this study lends a bit of weight to something economists at Goldman Sachs have been saying for a few months now about the workforce and opioids in general.

And the Federal Reserve's Beige Book has begun citing workers' inability to pass drug tests as a big reason some places couldn't find workers.

Again, this is likely one factor among many: Past research has blamed video games, higher rates of college attendance and technology's tendency to automate low-skill jobs out of existence.